Connected to wifi but still no internet connection

With a wired connection to the Mesa card and a wifi connection to the internet (or a second NIC) sometimes Linux gets confused about the correct route and tries to go out via the mesa connection. You may need to add a default route. I've just forgotten how to fix this.

Linked on this thread, just a speedy copy/paste action:
>>> If you want to use another connection or a wireless connection for internet, you have to set up everything as above, set up internet, and ONLY after having internet working edit the wired connection X going to Mesa card again as follows:
- network manager>edit connections>wired connection X>IPv4 settings> ROUTES > just click on the "use this connection only for resources on its network"> OK>save>network manager>reconnect to that network.